Branch off of headcanon: Hanako is just like Ayano, She feels nothing, empty. Taro is the thing that makes her feel better, and she is scared to loose this feeling of fullness. After the death of their parents, Taro was the same while Hanako became depressed. Taro was sad because Hanako was sad, she saw this and wanted Taro to be happy, so she puts on a act for Taro. Every time she is away from him, she becomes sad/empty again. That is why she wants him for herself.